LTR is an acronym that stands for "long-term relationship". It is commonly used in online dating sites and personal advertisements to express a persons desire for a committed, lasting connection with another individual. The term likely developed during the early age of Internet communication as part of the broader trend of using abbreviations to streamline and speed up text-based communication. LTR is relevant to both heterosexual and gay relationships.

It is important to note that LTR can also represent specific jargon in various industries. For example, in the technology sector, LTR may refer to "logic trunked radio," while in the health and fitness field, it could mean "local twitch response". However, in the context of dating sites, LTR signifies that someone is looking for a serious commitment, possibly leading to marriage or a deeper, long-lasting connection, rather than a casual hookup or a short fling.