Antonyms for the word "most preventing" include terms that suggest allowing, promoting, encouraging or permitting. Synonyms like enabling, facilitating, promoting, assisting and helping convey a sense of positive or constructive action in contrast to preventing, which suggests obstruction or impeding progress. Other antonyms include promote, support, assist, aid, encourage, and facilitate, all of which suggest actively assisting or helping progress along. In essence, the antonyms of "most preventing" imply a positive force, something that helps or supports progress towards a goal, in contrast to the negative force of preventing.