deadbolt
UK[ˈdedbəʊlt]US[ˈdedboʊlt]
n
a strong metal bar for locking a door, which is moved into place by turning a key or knob
Morpheme Breakdown
dead
bolt
dead
absolute, complete
bolt
a heavy arrow or a bar
Etymology
the word 'deadbolt' is a compound formed from two old english elements. 'dead' in this context evolved from its original sense of 'lifeless' to signify something absolute, unyielding, or complete, as seen in terms like 'dead end' or 'dead center'. 'bolt' originates from the old english word for a short, heavy arrow or a similar fastening pin. when combined, the term literally describes a lock mechanism that is a 'complete bar', emphasizing its solid, immovable nature once engaged, in contrast to a spring-latch which can be retracted easily. this compound perfectly illustrates the function of this type of lock through the semantic fusion of its components.
Analysis
Structure: dead + bolt
dead (old english, meaning 'absolute, complete'); bolt (old english, meaning 'a heavy arrow or a bar')
Examples
she slid the heavy deadbolt across the door for extra security.
the old door required a key to turn the deadbolt from both the inside and outside.
we installed a new deadbolt lock after the break-in.