Meaning:

老掉牙 (lǎo diào yá) very old; out of date; obsolete

Usage:

“老掉牙” 形容事物、言论等陈旧过时。常用作定语。

“老掉牙” means sth. or speeches are out of date. It often acts as an attribute.

Examples:

1. 关于他的新闻已经老掉牙了。

    Guānyú tā de xīnwén yǐjīng lǎo diào yá le

    The news about his was too old.

2. 你能不能不提这些老掉牙的事情，听着就烦！

    Nǐ néng bu néng bù tí zhèxiē lǎo diào yá de shìqing, tīngzhe jiù fán

    Can’t you speak of the business out of date, which makes me irritable?