simple past tense and past participle of open-hand

That part of the sea out of sight of land. / A sea open to all nations, i.e. not a mare clausum.

A theatre, or similar building, primarily used for staging opera.

(music) A lighter version of opera with a frivolous story and spoken dialogue. [from 18th c.]

Frank and candidly straightforward / Generous and kind / Emotionally receptive

A person who opens something. / A device that opens something; specifically a tin-opener/can-opener, or a bottle opener. / (in combination) An establishment that opens.

completely open / having no laws or law enforcement / unsettled or unresolved / vulnerable or unprotected / (sports) without the presence of opponents nearby

In an open manner, visibly, not covertly.

(grammar) A compound word with spaces in it, for example, high school, school bus, or science fiction.

(mathematics, physics) A differential operator,denoted ∆ and defined on ℝⁿ as 𝛥=∑ᵢ₌₁ⁿ(∂²)/(∂x_i²), used in the modeling of wave propagation, heat flow and many other applications.