【Chief】 , 【chieftain】 , 【head】 , 【headman】 , 【leader】 , 【master】  are comparable when they mean the person in whom resides authority or ruling power but they differ in their applications and associations.

【Chief】 is the most comprehensive of these terms, being applicable as a general term to anyone from an absolute monarch to one′s immediate superior.

Usually, however, the term is applied specifically to one who is supreme in power or authority over a tribe or clan or to the superior officer in a civil department or to one who is vested with authority and power to act by the organization over which he presides.

The phrase in 【chief】 is often added to a title, held by two or more, to indicate the one who is the first in authority.

【Chieftain】 has never obtained the generality of  【chief】 and still usually carries implications derived from its early and still leading application to the 【chief】 of a tribe, a clan, or of a primitive, savage, or barbaric group.

【Head】 , though seemingly as comprehensive as 【chief】 is applied most frequently to the person of a group who serves as its 【chief】 executive or on whose shoulders the responsibility finally rests.

【Headman】 comes close to  【chieftain】 in that it usually applies to the person who serves as the 【chief】 of his tribe or village; the term, even more than  【chieftain】 , implies a condition of savagery or barbarism.

【Leader】 implies headship, sometimes of a nation or people but more often of an organized body (as a political party, a society, or a band of musicians) or of an informal assembly (as of persons or animals).

The term usually implies a capacity for guidance, direction, or for the assumption of full control and of winning the support of those under one.

【Master】 , on the other hand, applies to a 【head】 who has another or others under him subject to his direction or control and necessarily obedient to his will: the term stresses his authority rather than his capacity for guidance.

In general use the term is applied as a designation to an employer of servants and to the 【head】 of a school or of a class. It is also applied generally to anyone who exerts great and controlling influence over others or who is regarded as one to be followed or obeyed.

The  【chief】 specific use of 【master】 is as the title of the person qualified to command a merchant vessel; in this use it is commonly superseded by captain as a courtesy title.