latch

[lach] /lætʃ/
noun
1.
a device for holding a door, gate, or the like, closed, consisting basically of a bar falling or sliding into a catch, groove, hole, etc.
verb (used with object)
2.
to close or fasten with a latch.
verb (used without object)
3.
to close tightly so that the latch is secured:
The door won't latch.
Verb phrases
4.
latch on,
  1. to grab or hold on, as to an object or idea, especially tightly or tenaciously.
  2. to include or add in; attach:
    If we latch the tax on, the bill will come to over $100.
5.
latch onto, Informal.
  1. to take possession of; obtain; get.
  2. to acquire understanding of; comprehend.
  3. to attach oneself to; join in with:
    The stray dog latched onto the children and wouldn't go home.
Origin
before 950; 1930-35 for def 5; Middle English lacchen, Old English lǣccan to take hold of, catch, seize; akin to Greek lázesthai to take
Related forms
relatch, verb (used with object)
British Dictionary definitions for latches

latch

/lætʃ/
noun
1.
a fastening for a gate or door that consists of a bar that may be slid or lowered into a groove, hole, etc
2.
a spring-loaded door lock that can be opened by a key from outside
3.
(electronics) Also called latch circuit. a logic circuit that transfers the input states to the output states when signalled, the output thereafter remaining insensitive to changes in input status until signalled again
verb
4.
to fasten, fit, or be fitted with or as if with a latch
Word Origin
Old English læccan to seize, of Germanic origin; related to Greek lazesthai
Word Origin and History for latches

latch

v.

Old English læccan "to grasp or seize," from Proto-Germanic *lakkijanan. Not found in other Germanic languages; probably from PIE *(s)lagw- "to seize" (see analemma). In its original sense the verb was paralleled in Middle English and then replaced by French import catch (v.). Meaning "to fasten with a latch" is mid-15c. Related: Latched; latching.

n.

a fastening for a door, etc., late 13c., probably from latch (v.).