1.  excavator(n = noun.person) - a workman who excavates for foundations of buildings or for quarrying;
is a kind of working man, working person, workingman, workman
Derived form verb excavate₃

2.  excavator(n = noun.artifact) digger, power shovel, shovel - a machine for excavating;
is a kind of machine
has particulars: backhoe, dredge, steam shovel
Derived form verb excavate₃

   One who, or that which, excavates or hollows out; a machine, as a dredging machine, or a tool, for excavating. [1913 Webster]

N  concavity, depression, dip, hollow, hollowness, indentation, intaglio, cavity, dent, dint, dimple, follicle, pit, sinus, alveolus, lacuna, excavation, strip mine, trough, honeycomb, cup, basin, crater, punch bowl, cell, socket, valley, vale, dale, dell, dingle, combe, bottom, slade, strath, glade, grove, glen, cave, cavern, cove, grot, grotto, alcove, cul-de- sac, gully, arch, bay, excavator, sapper, miner, honeycomb (sponge), depressed, alveolate, calathiform, cup-shaped, dishing, favaginous, faveolate, favose, scyphiform, scyphose, concave, hollow, stove in, retiring, retreating, cavernous, porous, infundibul, infundibular, infundibuliform, funnel shaped, bell shaped, campaniform, capsular, vaulted, arched.