from the OED:
ept, adj. Pronunciation: /ɛpt/ Etymology: Back-formation < inept adj.
Used as a deliberate antonym of ‘inept’: adroit, appropriate, effective.
1966 Time 30 Sept. 7/1 With the exception of one or two semantic twisters, I think it is a first-rate job—definitely ept, ane and ert.
1976 N.Y. Times Mag. 6 June 15 The obvious answer is summed up by a White House official's sardonic crack: ‘Politically, we're not very ept.’
The OED is a gold standard, though.
from the OED:
ept, adj. Pronunciation: /ɛpt/ Etymology: Back-formation < inept adj.
1938 E. B. White Let. Oct. (1976) 183, I am much obliged..to you for your warm, courteous, and ept treatment of a rather weak, skinny subject.1966 Time 30 Sept. 7/1 With the exception of one or two semantic twisters, I think it is a first-rate job—definitely ept, ane and ert.
1976 N.Y. Times Mag. 6 June 15 The obvious answer is summed up by a White House official's sardonic crack: ‘Politically, we're not very ept.’