VIRAL

Rapidly becoming popular online (5)

Solution has appeared in 2 crosswords (2 across and 0 down):

• Quick crossword No 16,084 — 2021-11-24 00:00:30
  11A: Circulated in a flash to a large audience on the internet (5)
• Quick crossword No 15,190 — 2019-01-14 00:00:22
  19A: Rapidly becoming popular online (5)