Verb

(persever)

To persist steadfastly in pursuit of an undertaking, task, journey, or goal, even if hindered by distraction, difficulty, obstacles, or discouragement.

* 1606 , , King Lear , act 3, scene 5:

I will persevere in

my course of loyalty, though the conflict be sore

between that and my blood.

* 1817 , , Persuasion , ch. 1:

Sir Walter had sought the acquaintance, and though his overtures had not been met with any warmth, he had persevered in seeking it.

* , "The Agonies of Writing a Musical Comedy":

He is a trifle discouraged, but he perseveres .

Verb

(es)

To be preoccupied with a single topic or emotion.

*{{quote-magazine, date=2014-06-21, volume=411, issue=8892, magazine=(The Economist)

, title= Magician’s brain , passage=The [Isaac] Newton that emerges from the [unpublished] manuscripts is far from the popular image of a rational practitioner of cold and pure reason. The architect of modern science was himself not very modern. He was obsessed with alchemy.}}

(label) To dominate the thoughts of someone.

To think or talk obsessively about.