sea 
(sē)
(sē)n.
Idiom: 1. The continuous body of salt water covering most of the earth's surface, especially this body regarded as a geophysical entity distinct from earth and sky.
2.
a. A tract of water within an ocean.
b. A relatively large body of salt water completely or partially enclosed by land.
c. A relatively large landlocked body of fresh water.
3.
a. The condition of the ocean's surface with regard to its course, flow, swell, or turbulence: a rising sea; choppy seas.
b. A wave or swell, especially a large one: a 40-foot sea that broke over the stern.
4. Something that suggests the ocean in its overwhelming sweep or vastness: a sea of controversy.
5. Seafaring as a way of life.
6. Astronomy A lunar mare.
at sea
1. On the sea, especially on a sea voyage.
2. In a state of confusion or perplexity; at a loss.
[Middle English see, from Old English sǣ.]
- downgrade
- downhaul
- downhearted
- downheartedly
- downheartedness
- downhill
- down-home
- down in/atthe mouth
- Downing
- Downing Street
- down in mouth
- downlink
- download
- downloadable
- down low
- downmarket
- down nose
- down on
- down (one's) nose
- down one's nose
- down on luck
- down on (one's) luck
- down on one's luck
- down payment
- downplay