What is the meaning of St.?

Alternative letter-case form of St., abbreviation of street.

abbreviation of starší (Senior”, “[the] Elder): Sr.

abbreviation of statt

abbreviation of stark

abbreviation of samtenging: conj. (conjunction)

abbreviation of stykki

abbreviation of stig

abbreviation of sankti

abbreviation of staddur

abbreviation of stofnaður

abbreviation of stycke (piece) or stycken (pieces): pc., pcs.

abbreviation of stor (large) or stora (the large)

nonstandard spelling of S:t (m. Saint) or S:ta (f. Saint)

Source: wiktionary.org