Abbreviated version of I reckon. Said in mid-conversation to agree with a previous staement or question. Be careful, however, innocent by-standers may think that you said erection. Example: Enrico and Bruce are out walking. Enrico sees a beautiful and busty woman walking in the distance. Enrico: Wow, see that babe, she's beautiful. Bruce: Irection. Bruce has just agreed with Enrico's comment.
IRECTION
Meaning of IRECTION in English
Slang English vocab. Английский сленговый словарь. 2012