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.

Abbreviation of stykki.

Abbreviation of stig.

Abbreviation of sankti.

Abbreviation of staddur.

Abbreviation of stofnaður.

Abbreviation of stycke (piece) or stycken (pieces); similar to pc. or pcs.

Abbreviation of stor (large) or stora (the large).

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

Source: wiktionary.org