From The Collaborative International Dictionary of English v.0.48 [gcide]:
Forenoon \Fore"noon"\, n.
The early part of the day, from morning to meridian, or noon.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
forenoon
n 1: the time period between dawn and noon; "I spent the morning
running errands" [syn: morning, morn, morning time,
forenoon]