The antonyms for the word "wast sweet on" can include words like hate, detest, despise, loathe, abhor, and disregard. These words convey a negative feeling towards something, rather than a sweet or fond feeling. When someone hates or detests something, they have a strong aversion towards it, and do not hold any positive feelings towards it. Similarly, someone who disregards something does not see its worth or value, and therefore does not hold any sweet feelings towards it. Antonyms such as hate, detest, and despise are powerful words that show a complete aversion towards something, in contrast to the sweet emotions associated with "wast sweet on.