1) All thumbs 2) All thumbs, so to speak 3) Awkward 4) Blundering 5) Bumbling 6) Bungle-prone 7) Bungling 8) Butterfingered 9) Butterfingery 10) Clueless 11) Clumsy 12) Clumsy as an ox 13) Clumsy in disturbing a pet 14) Clumsy, incompetent 15) Cumbersome 16) Decidedly unskillful 17) Displaying no dexterity 1) Amateurish 2) Awkward 3) Clumsy 4) Gauche 5) Inapt 6) Incompetent 7) Infelicitous 8) Klutzy 9) Maladroit 10) Poor 11) Unable 12) Unskilled 13) Useless 
• (a.) Not apt or fit; unfit; unsuitable; improper; unbecoming. • (a.) Silly; useless; nonsensical; absurd; foolish.
In·ept' adjective [ Latin ineptus ; prefix. in- not + aptus apt, fit: confer French inepte . Confer Inapt .] 1. Not apt or fit; unfit; unsuitable; improper; unbecoming. « The Aristotelian philosophy is inept for new discoveries.» Gl...
unskillful said or done at the wrong time 
[adj] - revealing lack of perceptiveness or judgment or finesse
tactless adjective revealing lack of perceptiveness or judgment or finesse; `an inept remark`; `it was tactless to bring up those disagreeable`
without skill or aptitude for a particular task or assignment; maladroit: He is inept at mechanical tasks. She is inept at dealing with people. · generally awkward or clumsy; haplessly incompetent. · inappropriate; unsuitable; out of place. · absurd or foolish: an inept remark.
[ASVAB glossary] revealing lack of perceptiveness or judgment or finesse