As used in this chapter the term:

(1) "Ancillary service" shall mean any cocurricular service or activity, any health care service or activity, and any other services or activities, except "courses," for or in which preschool through twelfth grade students are enrolled by a public school. The term shall include, but not be limited to, counseling, psychological services, testing, remedial instruction, speech and hearing therapy, health care services, tutorial services such as home or hospital instruction for the physically disabled, and sports activities;

(2) "Course" shall mean any instructional curricular service or activity in which preschool through twelfth grade students are enrolled by a public school;

(3) "Part-time public school student" shall mean a student who is enrolled in a public school for less time than a "full-time equivalent student" as defined in chapter 392-121 WAC, as now or hereafter amended, and shall include:

(a) Private school students to the extent they are also enrolled in a public school as a student thereof for the purpose of taking any course or receiving any ancillary service, or any combination of courses and ancillary services which is not available in the student's private school of attendance;

(b) Any student who is enrolled exclusively in a public school for the purpose of taking courses or receiving ancillary services and/or participating in a work training program approved by the board of directors of the district or charter school board; and

(c) Any student who is participating in home-based instruction to the extent that the student is also enrolled in a public school for the purpose of taking any course or receiving any ancillary service, or any combination of courses and ancillary services.

(4) "Private school" shall mean any nonpublic vocational school and any nonpublic school which provides instruction in any of the grades kindergarten through twelve inclusive of nonpublic sectarian (religious) schools;

(5) "Private school student" shall mean a student who is enrolled in a private school "full time" as defined by the private school of attendance; and

(6) "Home-based instruction" shall mean an instructional program established pursuant to RCW 28A.225.010(4).