\documentclass{article}
\usepackage{glossaries}
\makenoidxglossaries
%\tracingmacros=2\relax
%\tracingcommands=2\relax
%\newglossaryentry{poo}{name={poo},description={doodoo}}
%\tracingmacros=0\relax
%\tracingcommands=0\relax
\newglossaryentry{potato}{name={potato},plural={potatoes},
description={starchy tuber}}
\newglossaryentry{cabbage}{name={cabbage},
description={vegetable with thick green or purple leaves}}
\newglossaryentry{carrot}{name={carrot},
  description={orange root}}
\longnewglossaryentry{fishage}
{name={Fish Age}}
{%
A common name for the Devonian geologic period
spanning from the end of the Silurian Period to
the beginning of the Carboniferous Period.
This age was known for its remarkable variety of
fish species.
}
\setacronymstyle{long-short}
\newacronym{svm}{SVM}{support vector machine}
\begin{document}
First use: \gls{svm}. Second use: \gls{svm}. A use \gls{svm} within a sentence.
Chop the \gls{cabbage}, \glspl{potato} and \glspl{carrot}.
Or, more loudly: Chop the \Gls{cabbage}, \Glspl{potato} and \Glspl{carrot}.
Or, more loudly: Chop the \GLS{cabbage}, \GLSpl{potato} and \GLSpl{carrot}.
But do not use the \gls{fishage}; however, how about \glssymbol{fishage}?
\def\test#1{Word: #1; \xmakefirstuc{#1}; \MakeTextUppercase{#1}}%
\test{foo}.
\test{albatross}.
\printnoidxglossaries
\end{document}