er·gom·e·ter 
(ûr-gŏmĭ-tər)
(ûr-gŏmĭ-tər)n.
An instrument for measuring the amount of work done by a muscle or group of muscles.
[Greek ergon, work; see werg- in the Appendix of Indo-European roots + -METER.]
er′go·metric (ûr′gə-mĕtrĭk) adj.
- Forth
- for that matter
- forthcoming
- for the best
- for the better
- for the birds
- for the hell of it
- for the life of
- for the life of (one)
- for the life of one
- for the love of
- for the most part
- for the present
- for the time being
- forthright
- forthrightly
- forthrightness
- forthwith
- fortieth
- fortifiable
- fortification
- fortified wine
- fortifier
- fortify
- fortifyingly