clover
deuce-ace
leash
set of three
shamrock
tercet
ternary
ternion
terzetto
three
threesome
tierce
trefoil
trey
triad
trialogue
triangle
tricorn
trident
triennium
trihedron
trimester
trine
trinity
trinomial
trio
triphthong
triple crown
triple threat
triplet
triplopy
tripod
triptych
trireme
triseme
triskelion
trisul
triumvirate
triunity
trivet
troika
triple
decalogy
dilogy
ennealogy
heptalogy
hexalogy
octalogy
pentalogy
polylogy
tetralogy
anthology
high tide
novelet
verisimilitude