Sub·ac'id adjective [ Latin subacidus . See Sub- , Acid .] Moderately acid or sour; as, some plants have subacid juices. -- noun A substance moderately acid. Found on http://www.encyclo.co.uk/webster/S/218
slightly or moderately acid or sour: a subacid fruit. · (of a person or a person's speech, temper, etc.) somewhat biting or sharp. Found on https://www.infoplease.com/dictionary/subacid