without variation or change, in every case
"constantly kind and gracious"
"he always arrives on time"
without interruption
"the world is constantly changing"
With steadfastness; with resolve; in loyalty, faithfully.
"After years of drifting through different jobs, she decided to stay with her community garden constantly, tending it with unwavering dedication even during the harshest winters."
In plain English: Constantly means doing something over and over again without stopping for a long time.
"She constantly checks her phone during meetings."
Usage: Use constantly to mean repeatedly or without interruption over time, not to describe doing something with unwavering dedication or faithfulness. Reserve definitions involving steadfastness for words like steadfastly or loyally instead.
The word constantly comes from combining the adjective constant with the suffix -ly. It entered usage to replace an older native form that had a similar meaning.