SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ADVENT INTERNATIONAL CORP/MA (Last) (First) (Middle) PRUDENTIAL TOWER 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Definitive Healthcare Corp. [ DH ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 11/22/2021
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	11/22/2021		D		2,102,873(1)	D	$34.74	62,493,676(2)	I	See Notes(2)(3)(4)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* ADVENT INTERNATIONAL CORP/MA (Last) (First) (Middle) PRUDENTIAL TOWER 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Sunley House Capital Master Limited Partnership (Last) (First) (Middle) PRUDENTIAL TOWER 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Sunley House Capital GP LP (Last) (First) (Middle) PRUDENTIAL TOWER 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SUNLEY HOUSE CAPITAL GP LLC (Last) (First) (Middle) PRUDENTIAL TOWER 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SUNLEY HOUSE CAPITAL MANAGEMENT LLC (Last) (First) (Middle) PRUDENTIAL TOWER 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. See Exhibit 99.1 for text of footnote (1).

2. See Exhibit 99.1 for text of footnote (2).

3. See Exhibit 99.1 for text of footnote (3).

4. See Exhibit 99.1 for text of footnote (4).

Remarks:

Christopher Egan, a Managing Partner of Advent and Lauren Young, a Managing Director of Advent (together, the "Advent Directors"), each serve on the board of directors of the Issuer, and have been deputized to represent the Reporting Persons on the board of directors. By virtue of the Advent Directors' representation, for purposes of Section 16 of the Securities Exchange Act of 1934, each of the Reporting Persons may be deemed directors by deputization of the Issuer. The Advent Directors have filed separate Section 16 reports disclosing securities of the Issuer that they may be deemed to beneficially own for Section 16 purposes. Exhibit 99.1 (Footnotes to Form 4) and Exhibit 99.2 (Signatures and Joint Filer Information) are incorporated by reference. Form 5 of 5: This Form 4 is the fifth of five Forms 4 being filed relating to the same event. The Form 4 has been split into multiple filings because there are more than 10 Reporting Persons total, and the SEC's EDGAR filing system limits a single Form 4 to a maximum of 10 Reporting Persons. Each Form 4 will be filed by Designated Filer Advent International Corporation.

	ADVENT INTERNATIONAL CORPORATION, By: /s/ Neil Crawford, Name: Neil Crawford, Title: Director, Fund Administration	11/24/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
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