pipe n
1 conduit, conveyor, duct, hose, line, main, passage, pipeline, tube
2 briar, clay, meerschaum
3 fife, horn, tooter, whistle, wind instrument vb
4 cheep, peep, play, sing, sound, tootle, trill, tweet, twitter, warble, whistle
5 bring in, channel, conduct, convey, siphon, supply, transmit
→
tobacco
pipe down
belt up (slang) be quiet, button it (slang) button one's lip (slang) hold one's tongue, hush, put a sock in it (Brit. slang) quieten down, shush, shut one's mouth, shut up (informal) silence
pipe dream
castle in the air, chimera, daydream, delusion, dream, fantasy, notion, reverie, vagary
pipe up
have one's say, make oneself heard, put one's oar in, raise one's voice, speak, speak up, volunteer