The stage where a males phallic organ is enlarged to halfway "there" but not finished. Handy when diving into pools with loose pants or being pantsed in public.
Jessica Alba announced she will appear topless in her next film; I for one already have a semilobon.
by TheGreenFox July 27, 2008
the male penis is semi-erect :)
I got a semi lob on over jennifer lopez
by Stinkey July 09, 2003