Green’s Dictionary of Slang

(N.Z.) a portmanteau, a travelling bag.

1905		Truth (Wellington) 7 Oct. 7: Pack your ‘ports’ and hurry up [DNZE].
1943		J.B. Hislop Pure Gold and Rough Diamonds 107: One evening, on answering a knock on the homestead front door, he was met by a traveller with ‘port sammy’ all set for the usual kind invitation to come along inside.
1969		P. Newton Big Country of North Island 215: As green as grass, he arrived riding a horse bareback and carrying a flash Queen Street port sammy.
1980		M. Lawry Good Luck and Lavender 63: A classy gentleman’s travelling chest [...] had strong metal clasps and a lock, and a leather handle was attached to each end. [...] Ed nonchalently [sic] referred to this piece of elegant luggage as his ‘port sammy’ [DNZE].