|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|
|4.||to fasten, fit, or be fitted with or as if with a latch|
|[Old English læccan to seize, of Germanic origin; related to Greek lazesthai]|
Also, latch on to.
Get hold of, grasp; also, understand, grasp mentally. For example, They latched onto a fortune in the fur trade, or Carol quickly latched on to how the sewing machine works. [c. 1930]
Attach oneself to, join in with, as in Rob didn't know the way so he latched on to one of the older children. [c. 1930]