Condition or fitness. Can be thought of as an analogue to mettle, but regarding **f**unctional rather than **m**aterial qualities. Fettle is how something is made in contrast with mettle being what something is made from.

Found in the 25 Jan­u­ary 2014 edi­tion of *The Econ­o­mist*. The for­mer mil­i­tary dic­ta­tor of Pak­istan, Perez Mushar­raf, was described by doc­tors as being in «pret­ty good fet­tle» despite claims of a heart attack for which there was no evi­dence, and upon which his lawyers claimed he was not healthy enough to be tried for high treason.

Thanks go to *The Econ­o­mist* for expand­ing my vocab­u­lary, a task oth­er pub­li­ca­tions seem reluc­tant to take on.