I noticed that the list of theorems doesn't make much sense for definitions because what I get basically is just 1.5 Def etc. which doesn't convey any information. Hence I added the extra information as shown below so that I'd get 1.5 Def (Vector Space) in the list of theorems which helps me a lot actually. However it makes the text a bit less legible because now instead of Def. 1.5 I get Def. 1.5 (Vector Space) as expected. Is there a way to remove this additional information in the actual text but have it shown in the list of theorems?
\documentclass[10pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{thmtools}
\begin{document}
\listoftheorems[ignoreall,show={definition}]
\begin{definition}[Vector Space]
....
\end{defintion}
\end{document}

math.sty? Your own collection of math macros? – Dec 06 '15 at 21:20math.stythere is stuff like\usepackage{amsmath}– Gonenc Dec 06 '15 at 21:21\SkipTocEntrycomparable to what's explained in this answer: http://tex.stackexchange.com/a/24798/579. that would permit you to omit the optional argument todefinition, and insert it only for the toc. – barbara beeton Dec 06 '15 at 21:22