(aviation) Initialism of pilot-induced oscillation. / (electronics) Initialism of programmed input/output.

An island in Makira-Ulawa, Solomon Islands.

plural of PIO

A municipality of Albay, Philippines.

Of or pertaining to piety, exhibiting piety, devout, godfearing. / Relating to religion or religious works.

(physics) Any of three semistable mesons, having positive, negative or neutral charge, composed of up and down quarks/antiquarks.

Affected or exaggerated piety.

One who goes before, as into the wilderness, preparing the way for others to follow. / A person or other entity who is first or among the earliest in any field of inquiry, enterprise, or progress.

(transitive) To be the first to do or achieve (something), preparing the way for others to follow.

(physics, chemistry) an exotic atom equivalent to a hydrogen atom with the proton replaced by a pion / (physics) an onium where the bound antiparticle-particle pair is a pion and an antipion.