The Greek and Ge’ez that is typically translated as “gentleness” in English is translated in various ways:

• Suki: gitusaena inae or “not-snatching way” (source L. and E. Twyman in The Bible Translator 1953, p. 91ff. )
• Tibetan: sems dul ba (སེམས་​དུལ་​བ།), lit. “mind + tame” (source: gSungrab website )
• Ojitlán Chinantec: “make hearts good”
• Isthmus Mixe: “speak with patience”
• Tenango Otomi: “speak in a good way”
• Tabasco Chontal: “mind should be good with all” (source for this and three above: John Beekman & Harwood Hess in Notes on Translation, March 1963, p. 1ff.)

See also meek / meekness, spirit of gentleness and gentle and quiet spirit.