The phrase "crossed one's heart" is a promise or an oath. The antonyms of this phrase would be words that break a promise or negate an oath. Examples of such antonyms include "broke my promise," "lied," "cheated," "dishonest," and "unreliable." All of these antonyms signify a lack of trustworthiness and honesty, which is the opposite of the meaning conveyed by the phrase "crossed one's heart." In essence, the phrase "crossed one's heart" is a declaration of intention to keep a promise or fulfill an obligation, while its antonyms are expressions of betrayal, falsehood, recklessness, and unreliability.
