{%- comment -%}the splits and joins may occur immediately before
split and join filters parameter will vary(-,/,;,</p>) or be a passed variable `delimiter` set elsewhere {%- endcomment -%}
{%- assign value = "keyword" -%}
{%- assign string_with_value = "stringkeyword" -%}
{%- assign value_reversed =  value  | split: "" |  reverse |  join: "" -%}
{%- assign string_without_value = string_with_value | split: "" | reverse | join: "" | remove_first: value_reversed | split: "" | reverse | join: "" -%}

{%- comment -%} Sample output {%- endcomment -%}
value: {{ value }}
string_with_value: {{ string_with_value }}
value_reversed: {{ value_reversed }}
string_without_value: {{ string_without_value }}

{%- assign value = "keyword"  -%}
{%- assign string_with_value = "stringkeyword" | split:"" -%}
{%- assign string_without_value = "" -%}

{%- for character in string_with_value -%}
{%- if forloop.rindex <= value.size -%}{%- continue -%}{%endif-%}
{%- assign string_without_value = string_without_value  | append:character -%}
{%- endfor -%}

{% comment %} Sample output {% endcomment %}
value: {{ value }}
string_with_value: {{ string_with_value }}
string_without_value : {{ string_without_value }}

{% assign value = "keyword" %}
{% assign string_with_value = "stringkeyword" %}
{% assign truncate_size = string_with_value.size | minus: value.size %}
{{ string_with_value | truncate:truncate_size,"" }}