jackknife

A large clasp knife.

A dive in the pike position, in which the diver straightens out to enter the water hands first.

To fold or double (something or oneself) like a jackknife.

To cut or stab with a jackknife.

To bend or fold up like a jackknife.

To form a 90° angle.

A pocket-knife larger than a penknife.

A horn-handled clasp-knife with a laniard, worn by seamen.

A form of terminal used for making connections in central telephone-stations. See jack, 11 .

A large, strong clasp knife for the pocket; a pocket knife.