Persevere
Persevere , intransitive verb
[French persévérer, Latin perseverare, from perseverus very strict; per + severus strict, severe. See Per-, and Severe.]
To persist in any business or enterprise undertaken; to pursue steadily any project or course begun; to maintain a purpose in spite of counter influences, opposition, or discouragement; not to give or abandon what is undertaken.
Thrice happy, if they know
Their happiness, and persevere upright.