For an undated website I would like to remove (n.d.) from the citation and the reference. I tried to adapt the solution here to biblatex-chicago but I guess it is some other macros which will need to be redefined:
\documentclass{article}
\usepackage[authordate,backend=biber,indexing=true]{biblatex-chicago}
%\usepackage[style=authoryear-comp]{biblatex}
\usepackage{hyperref}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{lennon,
AUTHOR = "John Lennon",
TITLE = "Who did what in the Beatles"}
@online{google,
TITLE = "Google",
URL = "https://www.google.com"}
\end{filecontents}
\addbibresource{\jobname.bib}
\renewbibmacro*{date+extradate}{%
\ifboolexpr{test {\iffieldundef{labelyear}}
or (test {\iffieldequalstr{labelyear}{nodate}}
and test {\ifentrytype{online}})}
{}
{\printtext[parens]{%
\iflabeldateisdate
{\printdateextra}
{\printlabeldateextra}}}}
\renewbibmacro*{cite:labeldate+extradate}{%
\ifboolexpr{test {\iffieldundef{labelyear}}
or (test {\iffieldequalstr{labelyear}{nodate}}
and test {\ifentrytype{online}})}
{}
{\printtext[bibhyperref]{\printlabeldateextra}}}
\begin{document}
\textcites{lennon}{google}
\printbibliography
\end{document}


biblatex-chicagoandbiblatex-apacan be much harder to modify than the standard styles. – moewe Jul 28 '18 at 09:39