Lexical Definition

‎ματαιότης‎ mataiótēs (mat-ah-yot'-ace) futility ^G:N-F
from ‎μάταιος‎

vanity.

• inutility
• figuratively, transientness
• morally, depravity

Abbott-Smith

† ματαιότης, -ητος, ἡ (< μάταιος), [in LXX for הֶבֶל, Ps 30 (31):6* 38 (39):5* 61 (62):9*, al., and nearly 40 times in Ec; for שָׁוְא, Ps 25:4*, al.; רִיק, etc.;]
vanity, emptiness, frailty, folly: Ro 8:20, II Pe 2:18; τ. νοός, Eph 4:17 (elsewhere only in Pollux, 6, 134, and Eccl.).†

Abbott-Smith References

Liddell-Scott-Jones

ματαιότης, ητος, ἡ,

vanity, purposelessness, ματαιότης ματαιοτήτων [LXX+1st c.AD+]; folly, ἀνθρώπων [Refs 5th c.BC+]

_{LSJ Scripture Refs: LXX.Eccl.1.2 ☩ Rom.8.20}