Her backhand, however, had definitely improved.是什么意思？

Her backhand, however, had definitely improved.

不过她的反手球的确有了进步.

her

pron. (she的宾格)她，(she的所有格)她的，她，指某个国家，（一艘）船；

例句
There was a terrible sadness in her eyes...
她眼神中流露出深深的悲伤。

backhand

n. 反手，反手击球；

例句
You like to take backhand crosscourt and to run around and hit forehands off second serves.
你喜欢打反手穿越,大范围跑动然后正手接二发.

however

adv. 不管到什么程度，无论如何，然而，可是；conj. 不管怎样；

例句
The fact remains that inflation, however you measure it, is unacceptably high...
必须承认，无论怎么衡量，通货膨胀率都高得难以接受。

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

definitely

adv. 明确地，确切地，一定地，肯定地；int. （表强烈的肯定）当然；

例句
The description of one of the lads is definitely familiar. It rings a bell.
对其中一个小伙子的描述确实似曾熟悉。听起来挺耳熟。

improved

adj. 改良的；v. 改善，改进，提高( improve的过去式和过去分词 )，提高（土地、地产）的价值，利用（机会），抓紧（时间）；

例句
Air safety has not improved since the dramatic advances of the 1970s...
航空安全自从20世纪70年代得到显著提高之后，至今再没有任何改善。