(1) "Grandchild" means the minor child of a grandparent.

(2) "Grandparent" shall have the same meaning as provided in subsection (a) of Code Section 19-7-3 and shall include the biological great-grandparent or stepgreat-grandparent who is the parent or stepparent of a grandparent of a minor child.

(3) "Parent" shall have the same meaning as provided in Code Section 19-3-37. Such term used in the singular shall mean both parents if both parents share joint legal custody of the child, unless otherwise clearly indicated.

(4) "Reasonable evidence" means evidence that a reasonable person would find sufficient to determine whether one conclusion is more likely than another.

(5) "School" means:

(A) Any county or independent school system as defined in Code Section 20-1-9;

(B) Any private school as such term is defined in Code Section 20-2-690;

(C) A home study program meeting the requirements set forth in subsection (c) of Code Section 20-2-690;

(D) Pre-kindergarten programs; or

(E) Early care and education programs as such term is defined in paragraph (6) of Code Section 20-1A-2.

(6) "School term" means the part of the year in which school is in session.

(7) "Serious illness" means a physical or mental illness as determined by a licensed health care professional, including a psychiatrist or psychologist, that causes the parent to be unable to care for the minor child due to the physical or mental condition or health of the parent, including a condition created by medical treatment.

(8) "Terminal illness" has the same meaning as the term "terminal condition" as provided in paragraph (14) of Code Section 31-32-2.