Green’s Dictionary of Slang

1. (US black) one’s toes.

1944

D. Burley N.Y. Amsterdam News 13 May 6B: His groundgrabbers, ole man, rocked like Count Basie’s ‘One O’Clock Jump’ and the tens stared at his benders.

2. (US drugs) 10 mg amphetamine tablets.

1969		R.R. Lingeman Drugs from A to Z (1970) 240: tens Ten-milligram amphetamine tablets.
1981		D.E. Miller Bk of Jargon 339: tens: Amphetamines.
2001		ONDCP Street Terms 21: Tens — Amphetamine; methylenedioxymethamphetamine (MDMA).