Is “Slowest” a Scrabble word?
Yes
SLOWEST
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Slowest
/ˈsləʊɪst/
adjective
1.Taking a long time to move or go a short distance, or to perform an action; not quick in motion; proceeding at a low speed.
“a slow train; a slow computer”
2.Not happening in a short time; spread over a comparatively long time.
3.Of reduced intellectual capacity; not quick to comprehend.
Synonyms: careful, deliberate, prudent, boring, dilatory, dull
adverb
1.Slowly.
“That clock is running slow.”