From The Collaborative International Dictionary of English v.0.48 :
lunchtime \lunchtime\ n. the time for eating lunch; as, he observed a regular lunchtime. [WordNet 1.5]From WordNet (r) 3.0 (2006) :
lunchtime n 1: the customary or habitual hour for eating lunch; "he observed a regular lunchtime" [syn: lunchtime, lunch period]