WATER HAMMER
Wa"ter ham"mer. (Physics)

1. A vessel partly filled with water, exhausted of air, and hermetically sealed. When reversed or shaken, the water being unimpeded by air, strikes the sides in solid mass with a sound like that of a hammer.

2. A concussion, or blow, made by water in striking, as against the sides of a pipe or vessel containing it.

WATER HARE
Wa"ter hare. (Zoöl.)

Defn: A small American hare or rabbit (Lepus aquaticus) found on or near the southern coasts of the United States; — called also water rabbit, and swamp hare.

WATER HEMLOCK Wa"ter hem"lock. (Bot) (a) A poisonous umbelliferous plant (Cicuta virosa) of Europe; also, any one of several plants of that genus. (b) A poisonous plant () resembling the above.

WATER HEMP
Wa"ter hemp`. (Bot.)

Defn: See under Hemp.

WATER HEN
Wa"ter hen`.

1. (Zoöl.)