safety catch vs safety device

safety catch and safety device both are nouns.

Word	Noun	Adjective	Verb	Adverb
safety catch	Yes	No	No	No
safety device	Yes	No	No	No

As nouns, safety device is a hypernym of safety catch; that is, safety device is a word with a broader meaning than safety catch:

safety catch: guard consisting of a locking device that prevents a weapon from being fired
safety device: a device designed to prevent injury or accidents

Other hypernyms of safety catch include guard, safety.

safety catch (noun)	safety device (noun)
guard consisting of a locking device that prevents a weapon from being fired	a device designed to prevent injury or accidents