せえの

• (full) いっせーのせ, いっせえのせ (issē no se), いっせいのせ, 一(いっ)斉(せい)のせ (issei no se), いっせーのーせ (issē nō se)
• (shortening) いっせーの (issē no), いっせいの (issei no), せいのお, セイノー (sei nō)
• (Kansai) いっせーのーで (issē nō de), いっせえので, いっせーので (issē no de)
• (Kansai, shortening) せーのーで (sē nō de)

Shortening of いっせーのせ (issē no se). Ultimate derivation uncertain; thought to be from one or both of 一(いっ)斉(せい) (issei, “simultaneous”) and military use of French hisser (“to hoist”).

• (Tokyo) せえ・の [séꜜè nóꜜ] (Atamadaka + Atamadaka – [1]-[1])

• (Tokyo) せえの [séꜜènò] (Atamadaka – [1])
• IPA^(key): [se̞ːno̞]

せえの • (sē no) 

1. all together now!; one, two!; ready, set!