The phrase "hadst coming" is an archaic expression that was commonly used in the past. It is the combination of two words "hadst" and "coming." "Hadst" is an archaic form of the verb "have," while "coming" means arriving or approaching. Therefore, synonyms for this phrase may include "were arriving," "were coming," or "had arrived." Other possible alternatives may include "were on their way," "were en route," "had been expected," or "had made an appearance." These synonyms are more commonly used in modern-day vocabulary and can be used interchangeably to convey a similar meaning.