PUBLIC LAWS-CH. 120-JUNE 23,1947 44 Stat. 577. 45 U. S. C. §§151- 163,181-188 . Post, p. 140. obtained any other regular and substantially equivalent employment, but shall not include any individual employed as an agricultural laborer, or in the domestic service of any family or person at his home, or any individual employed by his parent or spouse, or any individual having the status of an independent contractor, or any individual employed as a supervisor, or any individual employed by an employer subject to the Railway Labor Act, as amended from time to time, or by any other person who is not an employer as herein defined. "(4) The term 'representatives' includes any individual or labor organization. "(5) The term 'labor organization' means any organization of any kind, or any agency or employee representation committee or plan, in which employees participate and which exists for the purpose, in whole or in part, of dealing with employers concerning grievances, labor disputes, wages, rates of pay, hours of employment, or conditions of work. "(6) The term 'commerce' means trade, traffic, commerce, trans- portation, or communication among the several States, or between the District of Columbia or any Territory of the United States and any State or other Territory. or between any foreign country and any State, Territory, or the District of Columbia, or within the District of Columbia or any Territory, or between points in the same State but through any other State or any Territory or the District of Columbia or any foreign country. " (7) The term 'affecting commerce' means in commerce, or burden- in or obstructing commerce or the free flow of commerce, or having led or tending to lead to a labor dispute burdening or obstructing commerce or the free flow of commerce. "(8) The term 'unfair labor practice' means any unfair labor prac- tice listed in section 8. "(9) The term 'labor dispute' includes any controversy concerning terms, tenure or conditions of employment, or concerning the associa- tion or representation of persons in negotiating, fixing, maintaining, changing, or seeking to arrange terms or conditions of employment, regardless of whether the disputants stand in the proximate relation of employer and employee. "(10) The term 'National Labor Relations Board' means the National Labor Relations Board provided for in section 3 of this Act. "(11) The term 'supervisor' means any individual having authority, in the interest of the employer, to hire, transfer, suspend, lay off, recall, promote, discharge, assign, reward, or discipline other employees, or responsibly to direct them, or to adjust their grievances, or effectively to recommend such action, if in connection with the foregoing the exercise of such authority is not of a merely routine or clerical nature, but requires the use of independent judgment. (122 The term 'professional employee' means- (a) any employee engaged in work (i) predominantly intel- lectual and varied in character as opposed to routine mental, manual, mechanical, or physical work; (ii) involving the con- sistent exercise of discretion and judgment in its performance; (iii) of such a character that the output produced or the result accomplished cannot be standardized in relation to a given period of time; (iv) requiring knowledge of an advanced type in a field of science or learning customarily acquired by a prolonged course of specialized intellectual instruction and study in an institution of higher learning or a hospital, as distinguished from a general academic education or from an apprenticeship or from training in the performance of routine mental, manual, or physical processes; or 138 [61 STAT.