latch (v.) Look up latch at Dictionary.com
Old English læccan "to grasp or seize, catch hold of," also "comprehend," from Proto-Germanic *lakkijanan. Not found in other Germanic languages; according to Watkins probably from PIE *(s)lagw- "to seize" (see analemma). In its original sense the verb was paralleled and then replaced by French import catch (v.). Meaning "to fasten with a latch" is mid-15c. Related: Latched; latching.
latch (n.) Look up latch at Dictionary.com
"device for catching and retaining," especially "a fastening for a door," late 13c., probably from latch (v.).