ultra-rare
adjective
(alsoultrarare)uk/ˌʌl.trəˈreər/us/ˌʌl.trəˈrer/veryunlikelyto beseen,experienced, etc.:
Theystumbledupon ultra-rarefootageof the band's firstconcert,playedwhen thememberswere still in highschooltogether.
Birdwatchers wereeagerfor aglimpseof the ultra-rarehawkthat was said tolivein theforest.
- He is theownerof an ultra-rarebaseballcardthat isworthalmost$200,000.
- Theaquariumishometo over three hundredspeciesofanimals,includingan ultra-rareexoticturtle.
- She had an ultra-rareskinconditionthat made her asubjectofinteresttomedicalresearchers.
Rarely & infrequently
- (every) now and then/againidiom
- blue moon
- ever and anon
- every
- few
- fit
- in/by fits and startsidiom
- occasion
- occasional
- occasionally
- odd
- odd jobs
- once
- one
- one-shot
- one-time
- rarely
- seldom
- ship
- time