(pretender)aster(suffix)

astrologaster   a foolish or petty astrologer
criticaster     inferior or petty critic
grammaticaster  a piddling grammarian
hereticaster    a petty or contemptible heretic
latinitaster    a petty scholar of Latin
logicaster      a petty logician
mathematicaster         minor or inferior mathematician
medicaster      quack; charlatan
militaster      soldier without skill or ability
musicaster      a mediocre musician
opiniaster      one who obstinately holds to an opinion
parasitaster    a mean or sorry parasite
philologaster   petty or contemptible philologist
philosophaster  amateur or superficial philosopher
poetaster       petty poet; writer of contemptible verses
politicaster    petty politician
rhetoricaster   petty rhetorician
scientaster     petty scientist
theologaster    petty or shallow theologian
usageaster      self-appointed and conservative language usage expert
witticaster     a petty or inferior wit