1. Having a horizontal surface in which no part is higher or lower than another; SYN. level, plane.
2. Having no depth or thickness.
3. Lacking variety in shading.
4. (Photography) Lacking contrast or shading between tones.
5. (Of a tire) Completely or partially deflated.
6. Stretched out and lying at full length along the ground; SYN. prostrate.
7. Parallel to the ground.
8. Not reflecting light; not glossy; SYN. mat, matt, matte, matted.
9. Without pleats; SYN. unpleated.
10. Having lost effervescence.
11. Not increasing as the amount taxed increases; SYN. fixed.
12. Not made with leavening; SYN. unraised.
13. (Music) Lowered in pitch by one chromatic semitone.

1. Against a flat surface.
2. At full length.
3. Below the proper pitch.
4. Wholly or completely.
5. With flat sails.

In music, a note or a key that is played lower in pitch than the written value, indicated by a flat sign or key signature. It can also refer to inaccurate intonation by a player.
1. A musical note or tone one half step lower than a specified note or tone.
2. A character on a line or space of the musical staff indicating a half step drop in pitch.

1. A deflated pneumatic tire; SYN. flat tire.
2. A level tract of land.
3. A notation indicating one half step lower than the note named.
4. A shallow box in which seedlings are started.
5. A wooden frame covered with painted canvas; part of a stage setting.