Words for nose and nostril in Celtic languages.

Proto-Celtic	*srognā = nose
Gaulish	*srognā = nose, nostril
Old Irish (Goídelc)	srón [sroːn] = nose, nostril
Irish (Gaeilge)	srón [sˠɾˠoːnˠ] = nose; sense of smell; prow, projection
Scottish Gaelic (Gàidhlig)	sròn [sdrɔːn] = nose, snout, trunk; promontory; snout (of a glacier); toe (of a shoe)
Manx (Gaelg)	stroin [strɛin] = nose, promontory, headland, ness, naze, nose-piece
Proto-Brythonic	*froɨn = nose
Middle Welsh (Kymraec)	ffroen = nostril
Welsh (Cymraeg)	ffroen = nostril; muzzle of a gun, mouth of a cannon, nozzle of a pair of bellows; hole, entrance, opening (of a pipe), cock, spout
Cornish (Kernewek)	frig [fri:g] = nostril
Old Breton	fron = nostril
Middle Breton	froan / fron = nostril
Breton (Brezhoneg)	froen = nostril fri = nose

Etymology: from Proto-Indo-European *sregʰ- (snore), from *welH- (to turn, to wind) [source].

Sources: Wiktionary, Am Faclair Beag, Online Manx Dictionary, Teanglann.ie, Geiriadur Prifysgol Cymru, Gerlyver Kernewek, Dictionnaire Favereau

Gaulish	*trugnā = nose
Welsh (Cymraeg)	trwyn [truːɨ̯n / trʊi̯n] = nose, snout; sense of smell
Old Cornish	trein = nose
Cornish (Kernewek)	tron [tro:n] = nose, point (of land), snout, tunnel
Breton (Brezhoneg)	stroen = dirt, snot

Sources: Wiktionary, Geiriadur Prifysgol Cymru, Gerlyver Kernewek

Words marked with a * are reconstructions.