respect is the regard, esteem, or deferential consideration extended to a person, group, quality, or rule — and, in a second and older sense, a particular aspect or detail of a thing, as in the phrase in every respect.
The relational sense runs in two directions that ordinary usage rarely separates. One is recognition of worth a person holds simply by being a person, which is the sense Immanuel Kant made central to modern moral philosophy when he grounded ethics in the dignity inherent in rational beings. The other is esteem earned through achievement, role, or conduct, which is conditional and can be withdrawn. Expressions of both vary sharply across cultures: some mark respect through formal address, honorifics, and ritual distance, others through the egalitarian informality that in a more hierarchical setting would read as its opposite.
The verb carries a third sense worth naming on its own — to refrain from interfering with, attested from the 1620s. Respecting a boundary, a treaty, a property line, or a stated no involves no esteem at all, only restraint. This is why the word does so much work in agreements: it names an action rather than a feeling.
The word entered English in the late fourteenth century meaning "relationship, regard, consideration," from Old French respect and Latin respectus, literally "the act of looking back at one," from re- ("back") and specere ("to look at") — the root behind spectacle, inspect, and suspect. The esteem sense is recorded by the 1580s. Respect is not 📝trust, which is a prediction about future conduct rather than an assessment of worth; nor is it obedience, which describes compliance regardless of what the complier thinks; nor admiration, which is enthusiastic where respect can be entirely cool.