Seek, search, scour, hunt, comb, ferret out, ransack, rummage are comparable when they mean to look for or go in quest of in the hope of finding.
Seek has become widely extended in application and may take as its object either a person or a concrete thing or something intangible or abstract and may imply either a quest that involves great effort or one that makes slight demands; the term is more often used in the written than the spoken language.
Search implies both effort and thoroughness. It differs from seek especially in taking as its object the place in which or the person on whom something is sought; it therefore connotes an investigating, an exploring, a penetrating scrutinizing, or a careful examining.
Scour, which means in general to run over or to traverse swiftly especially in pursuit or in search, can be used more narrowly to mean to make an exhaustive search of a territory or of something comparable to a territory for a thing that must be found.
Hunt basically comes close to scour in its general sense for it implies a pursuit of and often a search for something, but especially game. In the extended sense in which the term is here considered it implies specifically a vigorous and, often, unavailing search for something as elusive as game.
Comb implies methods of searching as painstaking or thoroughgoing as those involved in going through the hair with a fine comb.
Ferret out stresses the finding of something that is difficult to get at and usually suggests a vigorous, arduous, persistent and, often, tricky method of search.
Ransack and rummage imply a search usually of a limited area; both tend to stress the manner of going through what is examined and suggest a haphazard and often disorderly or heedless pulling about and turning over of miscellaneous items.
Though the two are often interchangeable, ransack is especially appropriate when one wishes to stress careless haste, lack of regard for the rights of others, or improper motives on the part of the searcher, while rummage may be chosen when a more neutral word is needed or when lack of a definite object of search is to be implied; thus, a thoughtless child might ransack the refrigerator to make himself a snack and then go rummage through his toys after a lost ball; a thief ransacks a house in search of loot, but rummages through a drawer with no clear and specific notion of what he may find.