containing an apology or excuse for a fault, failure, insult, injury, etc.: An apologetic letter to his creditors explained the delay.
2.
defending by speech or writing.
3.
willing or eager to apologize.
4.
sorry; regretful.
Also, a⋅pol⋅o⋅get⋅i⋅cal.
Origin: 1400–50; late ME apologetik a formal defense (< MF) < LL apologēticus written defense, defensive < Gk apologētikós fit for defense, equiv. to apologē- (var. s. of apologeîsthai to speak in defense; see apologia) + -tikos-tic
Offering or expressing an apology or excuse: an apologetic note; an apologetic smile.
Self-deprecating; humble: an apologetic manner.
Serving as or containing a formal justification or defense: an apologetic treatise on church doctrine.
n. A formal defense or apology.
[Middle English, formal defense, from Latin apologēticus, from Greek apologētikos, suitable for defense, from apologeisthai, to defend oneself verbally, from apologos, apology, story; see apologue.] a·pol'o·get'i·cal·ly adv.
[uh-pol-uh-jet-ik] 
