adjective insuportable, inaguantable, insostenible, insofrible, intolerable.

adverb
1. insuportablement.
2. it is unbearably hot fa una calor insuportable.
3. she is unbearably vain és insofriblement vanitosa.

adjective
1. [team, etc.] imbatible
2. [offer, price, etc.] immillorable

adjective
1. [team] imbatut, invencible.
2. [army] invicte.
3. [price] immillorable.

adjective
1. indecorós, impropi.
2. [dress, etc.] que no li està bé a algú, que no li cau bé a algú.
3. it is unbecoming to + infinitive no és elegant  + infinitiu.

adjective unbeknown to me sense que jo ho sabés.

noun
1. Religion [in general] descreença.
2. [of person] manca de fe.
3. [astonishment] incredulitat.

adjective
1. increïble.
2. it is unbelievable that... és increïble que... + subjuntiu

adverb increïblement.

noun no creient, descregut, descreient.