(+ in/into) to impart (something) gradually
She was a gifted teacher, instilling in children a love of learning
to cause (something) to enter drop by drop
Instil the medication into the infected eye
instillation /-ʹlaysh(ə)n/ noun
instilment noun
[early French instiller from Latin instillare to drip, from in-2 + stillare to drop, from stilla a drop]