it could mean choose a different/stronger word, your spelling is off, or it's in the wrong form of context. ex: Their very funny. but it should be They're very funny.
Do you mean obsequious? or subsequently? Even this editor underlines "subsequious" with red.
It means someone needs a proofreader.
Font Style
Redactor, proofreader, reviser, copyreader...
an inequality is a equation simalr to a normal one but the to equations are not = they use they signs < > = sin with a line trough it and < > signs with underlines
<u> in HTML underlines the specified text.
The person who had administered the three lines is merely trying to add emphasis to the word, drawing your attention to it. Eg. A teacher might be correcting a mistake made in a report, such as getting an answer wrong or spelling a word incorrectly.
Proofreaders
If it underlines the word as incorrect, and your tired of it coming up incorrect if its right, you can right click it and add it to dictionary.
It does not open any pane but red underlines it. It is according to the dictionary and shows the suggestions.
Spell check underlines misspelled and unknown words with a red line. Grammar check underlines grammatically incorrect sentences.
I've looked everywhere and the word "spiltered" doesn't have a meaning--it even underlines in red when I type it here.