Hammer-less a. : Without a visible hammer; -- said of a gun having a cock or striker concealed from sight, and out of the way of an accidental touch.

Example:
What year is an ITHACA Hammer Less 12 gauge serial 112216?

Taxonomy
hammer, Dictionary, Firearms, gun, striker, sight, Unanswered questions, Hammer Films, Webster 1913, The Hammer, Search, Patrick J. Cassidy, businessman, comic strip, Company, Press Room, Privacy Policy, IP Issues.

Defination from the web:
less a. (Firearms) Without a visible hammer; -- said of a gun having a cock or striker concealed from sight, and out of the way of an ... Hammer blow. List of left-wing publications in the United Kingdom. Medical treatment during the Second Boer War. Track and field athletics ...