sublinear
/ˌsʌbˈlɪnɪə/adjective
1 Botany and Zoology. Almost linear.
2Of punctuation, diacritics, etc.: placed below the line of printing or writing. Opposed to superlinear.
Origin
Mid 18th century; earliest use found in John Hill (bap. 1714, d. 1775), physician and actor. From sub- + linear.