The phrase "most slinking" signifies somebody or something that is sneaky or prone to hiding. Antonyms for this phrase would thus be terms like "open," "straightforward," "frank," or "honest." Respectively, these words suggest a person who is honest and clear, not concealing anything or attempting to deceive people. Such a person would be bringing their true self to the forefront, rather than remaining hidden behind a false façade. Other antonyms for "most slinking" could include words like "visible," "forthcoming," and "bold," which connote a sense of openness and transparency, rather than sneakiness or subterfuge.