null的过去分词是：nulled。null的详尽释义是adj.(形容词)无效的，无效力的，无用的，无益的无价值的无束缚力的等于零的，零值的【数】零的，空的没特征的，没表情的不存在的，没有的零（位）的毫不引起注意的无法律效力的。null【近义词】worthless无价值的。
一、详尽释义点此查看null的详细内容
二、英英释义
"it looked like nothing I had ever seen before"
"reduced to nil all the work we had done"
"we racked up a pathetic goose egg"
"it was all for naught"
"I didn't hear zilch about it"
"null and void"
三、词典解释
1.(协议、宣言或选举结果)无法律效力的，无效的
If an agreement, a declaration, or the result of an election isnull and void, it is not legally valid.
e.g. A spokeswoman said the agreement had been declarednull and void...
女发言人称该协议已宣布无效。
e.g. The declaration wasnull and void as it was proclaimed in completely illegal circumstances.
该声明无效，因为它是在完全非法的情况下宣布的。
四、例句
Their actions rendered the contract null and void.
他们的行为使合同无效。
The marriage was declared null and void.
婚姻已宣告无效了。
The path must end with a null character.
该路经必须以零结尾。
Vomit in null gravity wouldn't be fun.
如果在零重力下呕吐了可不是件好笑的事。
A null reference pointer was passed to the stub.
向占位程序传送了空的索引指针。
Primary keys do not allow null values.
主键不允许空值。
五、词汇搭配
六、经典引文
Its influence on that element was absolutely null.
出自：J. Pinkertonnull的相关近义词
worthless、invalid、valueless、insignificant、useless、void、null and void、unacceptable、unsound、untrue、unimportant、ineffectual、nonexistent、piddling、inoperative、immaterial、blank、trivial、inexistent、clear、hollow、trifling、no-good、inutile、bare、empty、unsubstantial、unprofitable、foolish、good-for-nothing、vacuous、nugatory、inane、purposeless、inconsequential、futile、senseless、unavailing、inefficacious、extinguished、destroyed、annihilated、expunged、obliterated、exterminated、effaced、dissolved、extirpated、eliminated、binding、not、naught、Nada、Zippo、nil、nix、goose egg、zip、aught、cipher、zero、nothing、zilch、cypher
null的相关临近词
nullify、nuke、nulla、Nulli、nully、nullo、nullor、nullah、nullity、nullius、nulling、nullset