Lazy is the negative strongest connotations i think
A Telecommunications device for the deaf (TDD) is a teleprinter, an electronic device for text communication over a telephone line, that is designed for use by persons with hearing or speech difficulties. Other names for the device include teletypewriter (TTY), textphone (common in Europe), and minicom (United Kingdom).
The typical TDD is a device about the size of a typewriter or laptop computer with a QWERTY keyboard and small screen that uses an LED, LCD, or VFD screen to display typed text electronically. In addition, TDDs commonly have a small spool of paper on which text is also printed — old versions of the device had only a printer and no screen. The text is transmitted live, via a telephone line, to a compatible device, i.e. one that uses a similar communication protocol.
Formal and informal language serve different purposes. The tone, the choice of words and the
way the words are put together vary between the two styles. Formal language is less personal
than informal language. It is used when writing for professional or academic purposes like
university assignments. Formal language does not use colloquialisms, contractions or first person
pronouns such as ‘I’ or ‘We’.
Informal language is more casual and spontaneous. It is used when communicating with friends or
family either in writing or in conversation. It is used when writing personal emails, text messages
and in some business correspondence. The tone of informal language is more personal than
