Fear mór leabhar (male); Bean mhór leabhar(female).
or Leabharbhách (bibliophile)
also Leabharghealt (bibliomaniac).
In Irish you might say 'Táim buíoch díot faoin leabhar'. (I am grateful to you for the book). In Scottish Gaelic: ?
In Irish it's "Paidir na leannán as Gaeilge"
leabhar
ritavocamtamagoche
Caidé mar atá an leannán anocht? (Ulster Irish)
leannán
Compánach - companion fear céile - husband bean chéile - wife leannán - lover
Please specify Irish Gaelic or Scottish Gaelic: they are two separate languages.
leannán
Leannan or bràmair
Celtic is not a language, it is a group of languages 6 in all Welsh, Cornish, Breton Irish Gaelic, Scots Gaelic, Manx Gaelic You have to be a bit more specific
Irish Gaelic: salacharScots Gaelic: salachar