The word "gaugeable" means something measurable or able to be assessed. Therefore, antonyms for "most gaugeable" would be words that describe things that cannot be measured or assessed. Some possible antonyms could include immeasurable, intangible, imprecise, intangible, indeterminate, or incalculable. For instance, subjective experiences such as love, joy, and grief cannot be accurately measured or gauged, making them antonyms of "most gaugeable." On the other hand, qualities like transparency, clarity, and precision are opposites of imprecise, intangible, or indeterminate and may be more suitable for describing things that are most gaugeable.