Tinker's cuss is a British slang phrase that is used to express mild annoyance or frustration. It is not a widely recognized term, and as such, there are no official synonyms for it. However, there are various alternative phrases that can be used in place of tinker's cuss to convey similar meaning. These could include phrases like darn it, shoot, drat, gosh darn it, and heck, amongst others. These terms are generally considered to be less vulgar than using swear words, and may be more appropriate in certain social situations. Ultimately, the choice of synonym will depend on the individual's personal preference and the context in which the phrase is being used.