Constantly means all the time, without a break. The tap that drips constantly through the night, a phone buzzing constantly through dinner, a dog that barks constantly the moment you leave the house.
Two shades live in it. The strict one is unbroken — the pump runs constantly, the ice is constantly melting. The looser one is over and over: 'he is constantly late', which nobody hears as every second of the day. Notice what it attaches to — constantly lands on the things that irritate the speaker, the dripping, the interrupting, the being late. The adjective behind it is constant, which does double duty as a noun in maths and science, where a constant is a number that never moves.
1adverbconstantlyAll the time, without stopping.
“The fan hums constantly in the background.”
synonyms: continuously, perpetually, nonstop
2adverbrepeatedlyAgain and again; very frequently.
“He constantly forgets where he put his glasses.”
synonyms: repeatedly, continually
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: continually
Constantly is constant with -ly bolted on the end. It pushed aside the older native English adverb singallīċe, which had been saying the same thing in Old English clothes.
Latin
constantem
Old French
constant
Middle English
constant
English
constant
English, today
constantly
Built from
From constant + -ly. Displaced native singallīċe. constant comes from Middle English constant, from Old French constant, from Latin constantem, accusative of constans, from consto (“to stand firm”). Displaced native singal.
Etymology from Wiktionary, CC BY-SA