1 flat /ˈflæt/ adjective
flatter; flattest
1 flat
flatter; flattest
Learner's definition of FLAT
: having a smooth, level, or even surface : not having curves or bumps
: having a wide, smooth surface and little thickness
also of a shoe : having a flat heel or no heel
: spread out on or along a surface
: very clear and definite : absolute
◊ In British English the expression and that's flat! is used to stress that a statement or decision is definite and will not be changed.
: not changing in amount
: not having much business activity
: not having much interest or energy : dull
of a drink : no longer having bubbles
of a tire : not having enough air
: lower than the true pitch
: lower than a specified note by a semitone compare 1natural 8, 1sharp 13
of lighting conditions : not producing strong shadows
British, of a battery : no longer producing electricity : dead

(as) flat as a pancake

: very flat

— flatly


— flatness

noun [noncount]
2 flat /ˈflæt/ noun
plural flats
2 flat
plural flats
Learner's definition of FLAT
: a level area of land usually plural
: a flat part or surface
: a musical note that is one semitone lower than a specified note
: a written symbol ♭ that is placed before a note to show that it should be played a semitone lower compare 2natural, 3sharp
US : a shallow box in which young plants are grown
chiefly US : a shoe or slipper that has a flat heel or no heel usually plural
chiefly British : an apartment typically on one floor compare apartment
: a tire that does not have enough air
3 flat /ˈflæt/ adverb
3 flat
Learner's definition of FLAT
: on or against a flat surface
: in the position of someone or something that is lying spread out on the ground or another surface
: exactly or precisely used to describe something that happens quickly
informal : completely or absolutely
see also flat out
: below the correct musical pitch compare 2sharp 2

fall flat

see 1fall