from bottom of heart (adverb) sincerely: seriously, honestly
Sinonime: arguable, between rock and hard place, between sixes and sevens, betwixt and between, bone of contention, borderline, chancy, contestable, disputable, doubtful, dubious, iffy, in dispute, moot, mootable, open to question,
problematic, problematical, questionable, the jury's out, touch and go, uncertain,
undecided,
unsettled, up for discussion
Antonime: certain, inarguable, incontrovertible, indubious, questionable,
sure, uncontestable, undoubted