Meaning of LATCH in English
1》 a bar with a catch and lever used for fastening a door or gate.
2》 a spring lock for an outer door, which catches when the door is closed and can only be opened from the outside with a key.
3》 Electronics a circuit which retains whatever output state results from a momentary input signal until reset by another signal.
1》 fasten with a ~.
2》 Electronics (of a device) become fixed in a particular state.
3》 ( ~ on ) informal understand the meaning of something.
4》 ( ~ on to ) informal attach oneself to (someone) as a constant companion.
↘take up (an idea or trend) enthusiastically.
5》 ( ~ on ) (of a breastfeeding baby) manage to get its mouth into the correct position around the nipple.
on the ~ chiefly Brit. (of a door or gate) closed but not locked.
OE læccan 'take hold of, grasp', of Gmc origin.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004