(adv.) At that occurrence or event; on that account.
Example Sentences:
(1) Factors and methods being complementary and such having an effect of contrary sence are thereat especially described.
Whereon
Definition:
(adv.) On which; -- used relatively; as, the earth whereon we live.
(adv.) On what; -- used interrogatively; as, whereon do we stand?
Example Sentences:
(1) With the patient in a supine position, the droplets could be positioned over the macula in the preretinal vitreous space, whereon the FTBA PO2 could be influenced by the preretinal oxygen concentration.
(2) The heart was the only one of all the internal organs whereon significant pathologic changes were observed during autopsy.