What is Quasi Judicial?

Legal Definition
1) A proceeding conducted by an administrative or executive official that is similar to a court proceeding, e.g. a hearing. A court may review a decision arising from a quasi-judicial proceeding.

2) A judicial act performed by an official who is either not a judge or not acting in his or her capacity as a judge.
Illustrative caselaw
See, e.g. Intel Corp. v. Advanced Micro Devices, Inc., 542 U.S. 241 (2004) and Humphrey's Ex'r v. United States, 295 U.S. 602 (1935).
See also
Legal Definition
The acts of an officer that take on a judicial quality. The officer is authorised to act in such a way.
Legal Definition
A term applied to the action, discretion, etc., of public administrative officers, who are required to investigate facts, or ascertain the existence of facts, and draw conclusions from them, as a basis for their official action, and to exercise discretion of a judicial nature. See Bair v. Struck, 29 Mont. 45, 74 Pac. 69, 63 B R. A. 481; Mitchell v. Clay County, 69 Neb. 779. 96 N. W. 078; De Weese v. Smith (a C.) 97 Fed. 317. As to judicial "Day," "Deposit," "Discretion," "Documents," "Evidence," "Factor," "Mortgage," "Notice," "Process," "Sales," "Sequestration," and "Writs," see those titles.
-- Black's Law Dictionary
Legal Definition
The sort of authority or discretion vested in an officer wherein his acts partake of a judicial character. See 60 Conn. 448, 25 Am. St. Rep. 337, 22 Atl. 494.
-- Ballentine's Law Dictionary