Altho, conj.
Although. [Reformed spelling]
Shades of meaning
Fernald lists altho only as an antonym, under because.
Where he writes about it:
Tho and altho make as little as possible of the concession, dropping it, as it were, incidentally; as, "tho we are guilty, thou art good;" to say "we are guilty, but thou art good," would make the concession of guilt more emphatic. — from notwithstanding
Synonyms
none given