• (a.) Coming after the sun has passed the meridian; being in, or belonging to, the afternoon. (Abbrev. P. M.) • (a.) Fig., belonging to the after portion of life; late. Found on http://thinkexist.com/dictionary/meaning/postmeridian/
Post`me·rid'i·an adjective [ Latin postmeridianus ; post after + meridianus . See Meridian .] 1. Coming after the sun has passed the meridian; being in, or belonging to, the afternoon. (Abbrev. P. M. ) 2. Fig., belonging to the after portion of li... Found on http://www.encyclo.co.uk/webster/P/134
postmeridian, postmeridiem (P.M.) 1. Occurring after noon or midday; of or pertaining to the afternoon. 2. After midday; applied to the hours between noon and midnight; usually abbreviated pm or p.m. Found on http://www.wordinfo.info/words/index/info/view_unit/1271/6