[fos.ter] adj [ME, fr. OE fostor-, fr. fostor food, feeding; akin to OE foda food] (bef. 12c): affording, receiving, or sharing nurture or parental care though not related by blood or legal ties
[2]foster vt fos.tered ; fos.ter.ing (12c) 1: to give parental care to: nurture
2: to promote the growth or development of: encourage -- fos.ter.er n