General synonyms:
* Endeavor: To make a serious attempt to do something.
* Effort: Physical or mental exertion.
* Attempt: To try to do something.
* Work hard: To put in a lot of effort.
* Labor: To work hard and long.
* Hustle: To work hard and energetically.
* Push: To make a strong effort.
* Battle: To struggle against difficulties.
* Contend: To struggle against someone or something.
* Compete: To try to win something.
More specific synonyms:
* Aspire: To have a strong desire to achieve something.
* Aim: To have a goal or purpose.
* Seek: To try to find something.
* Grapple: To struggle to deal with a difficult problem.
* Fight: To struggle against something or someone.
* Pursue: To follow or chase after something.
* Clutch: To try desperately to hold on to something.
* Yearn: To have a strong desire for something.
The best synonym will depend on the specific context of your writing.