Green’s Dictionary of Slang

1. a rate of movement, a pace; thus fair/good clip, a (reasonably) high speed.

1833		S. Smith Major Downing (1834) 199: There isn’t a horse in this country that could keep up with us, if he should go upon the clean clip.
1868		H.W. Woodruff Trotting Horse of America 79: It is believed that he can go a four-minute clip.
1877		E. Peacock Gloss. Manley in Pubs. EDS 61/2: Clip, (1) speed, rapid motion. ‘We are goin’ wi’ a clip now ’.
1893		Field 25 Feb. 295/3: In three days I could drive him any ‘clip’ I chose by just talking to him [OED].
1900		A.H. Lewis ‘Crime That Failed’ in Sandburrs 81: He sprints for d’ nearest p’lice station at a 40 clip.
1906		S. Ford Shorty McCabe 99: There we were poundin’ over the rails through Pennsylvania at a mile-a-minute clip.
1915		Bulletin (Sydney) 7 Oct. 48/1: [H]e heard a noise in the air like the distant sound of an express train approaching at a sixty-mile clip.
1925		Wodehouse Carry on, Jeeves 11: You would find him prowling about the house, setting such a clip to try and catch up with himself.
1933		‘Goat’ Laven Rough Stuff 98: We watched the freight trains go through, they were going at a fairly slow clip.
1943		H.A. Smith Life in a Putty Knife Factory (1948) 160: She talks at a fearful clip.
1957		T. Powell ‘Somebody’s Going to Die’ in Best of Manhunt (2019) [ebook] You know we’ve been spending at a heavy clip [...] That house was costly.
1958		D. Stivens Scholarly Mouse and other Tales 67: [He] went off with the rag, at his fast clip.
1969		D. Pendleton Executioner (1973) 68: The big cars eating the pavement at a steady eighty-mile-per-hour clip.
1978		P. Theroux Picture Palace 217: The city cruised along at a good clip.
1995		C. Hiaasen Stormy Weather 9: The traffic began to move at a better clip.
2000		F. Kellerman Stalker (2001) 497: She got on the freeway, and pressed the pedal to the metal until she was going at a good fast clip.

2. (US) a smart, clever or lively young woman or man [ext. of sense 1].

1901		Monroe & Northup ‘College Words and Phrases’ in DN II:iii 138: clip n. A lively girl; ‘she’s a clip’.
1905		H. Green Actors’ Boarding House (1906) 143: Jimmy and Harold, who were songwriters and a pair of regular clips, sat down at the piano.
1922		in DARE.
1933		‘Notes & Quotes’ in AS VIII:3 72: A clip. A shrewd girl.
1960, 1975		Wentworth & Flexner DAS.

3. (US campus) a situation.

1901

Monroe & Northup ‘College Words and Phrases’ in DN II:iii 138: clip, n. ‘It’s an awful clip,’ an awful case, situation.