billfish 
noun (plural same or billfishes)
A large, fast-swimming fish of open seas, with a streamlined body and a long pointed spear-like snout. It occurs on the surface in warmer waters and is a popular sporting fish.
- Family Istiophoridae: three genera and several species, including the marlins, sailfish, and spearfish.
- Fish species like tunas, seerfishes, billfishes and mackerels fall in this category.
- The fastest-swimming fish are the billfish and the tunas.
- turn (or put) back the clock
- turn (or tighten) the screw (or screws)
- turn out
- turnout
- turn over
- turnover
- turn over a new leaf
- turnpike
- turnpike road
- turnround
- turn round and do (or say) something
- turn signal
- turnsole
- exodermis
- exodus
- exoenzyme
- ex officio
- exogamous
- exogamy
- exogenic
- exogenous
- exogenously
- exoglossic
- exon
- exonerate