[UN-1 9.] Of a sink or drain: Not fitted with a trap.
1850. Flor. Nightingale, Nursing, 15. An untrapped sink may … spread fever … among the inmates of a palace.
1877. Teale, Dangers to Health, 7. A rain water tank, which had an untrapped overflow into the drain.
1884. 19th Cent., May, 847. Untrapped drains.
