WordNet sense 1 (a writ issued by authority of law; usually compels the defendant's attendance in a civil suit; failure to appear results in a default judgment against the defendant):

summons

WordNet sense 2 (a mental process that you are not directly aware of):

unconscious process

WordNet sense 3 ((psychology) the performance of some composite cognitive activity; an operation that affects mental contents):

operation, cognitive operation, cognitive process, mental process

WordNet sense 4 (a natural prolongation or projection from a part of an organism either animal or plant):

appendage, outgrowth

WordNet sense 5 (institute legal proceedings against; file a suit against):

action, litigate, sue

WordNet sense 6 (march in a procession):

march

WordNet sense 7 (shape, form, or improve a material):

work, work on

WordNet sense 8 (deliver a warrant or summons to someone):

serve, swear out

WordNet sense 9 (a particular course of action intended to achieve a result):

procedure

WordNet sense 10 (subject to a process or treatment, with the aim of readying for some purpose, improving, or remedying a condition):

treat

WordNet sense 11 (a sustained phenomenon or one marked by gradual changes through a series of states):

physical process