Green’s Dictionary of Slang

1. a large, bushy moustache, supposedly reminiscent of the animal.

1922		Eve. Teleg. (Dundee) 9 Oct. 2/4: Offending ‘Walrus’. Mr Justice Day’s pet aversion was a counsel with a moustache.
1935		Tamworth Herald 16 Feb. 10/6: The Walrus. You have probably heard of a man having a ‘walrus moustache’.
1950		C. Harris Three-Ha’Pence to the Angel 67: She frowned at the wet crystals on his moustache [...] Penton transferred his black tin box to the other hand, and brushed his walrus-fall.
1960		Wodehouse Jeeves in the Offing 31: I wouldn’t say the moustache softened his face, but being of the walrus or soup-strainer type it hid some of it.
1984		P. Slabolepszy ‘Under the Oaks’ in Mooi Street (1994) 30: Ou Lamby had a walrus. Vive Zapata!!
1992		A. Duff One Night Out Stealing 86: Jube downing half a glass in a gulp. Mmm-uh! Wiping the spots from his walrus.

2. (US) a short, fat person.

1932		L.W. Merryweather ‘Argot of an Orphans’ Home’ in AS VII:6 403: wally, n. A short, fat person. walrus, n. Same as wally.
1938		D. Runyon ‘The Lemon Drop Kid’ in Runyon on Broadway (1954) 374: No. 2 is an old walrus by the name of The Democrat.

3. (Irish) £50.

2001

G. Coughlan Everyday Eng. and Sl. 🌐 Walrus (n): fifty pounds in money.