ADJ.
adjusted, standard
VERB + FOCUSSING
continued
FOCUSSING + NOUN
knob
PREP.
on, with
adj
Alternative spelling of focusing.
The bacteriologist adjusted the focussing knob on the microscope.
noun
At the time of the accident, the searchlight signals here were fitted with standard narrow-beam focussing, aimed at a train within 70yd of the signal.
noun — the concentration of attention or energy on something
I continued focussing on it, wondering if there was a way to get in and learn its secrets.