1
general::
quickly
at a high speed or without taking much time:
• The stream was flowing quite quickly. • They quickly became friends.
fast
at a high speed – used especially when talking about how something moves:
• You're driving too fast! • He ran home as fast as he could.
quick
spoken quickly – used in exclamations or in comparatives:
• Quick! There’s a mouse!
swiftly
written quickly:
• The government acted swiftly. • She was surprised that he agreed so swiftly.
rapidly
quickly – used especially about changes, increases, improvements etc:
• The population is growing rapidly. • a rapidly changing world
speedily
quickly and therefore efficiently:
• All problems were speedily dealt with.
briskly
quickly and energetically:
• He walked briskly back along the path.
at high/great speed
at a very fast speed – used especially in technical descriptions:
• The molecules are travelling at great speed.
at a rapid rate
especially written quickly – used about changes, increases, improvements etc:
• Internet shopping is growing at a rapid rate.
as quick as a flash/in a flash
extremely quickly:
• As quick as a flash, I was back in my bed and under the covers.
like lightning
moving extremely quickly:
• Like lightning, the cat darted under the bushes.
flat out
especially British English at the fastest speed possible:
• The car was going flat out. • He was running flat out.
Longman-Thesaurus