Searchable Drop down list

If you have Excel 365, this can be done with dynamic arrays but your profile says you're on 2010. You can also use VBA.

Here's my non-VBA workaround
Simply set up a Pivot Table in Sheet1 with "Description in both the ROWS quadrant and in the filter. When you open the filter, there's the option to search. In the example spreadsheet, I searched on "gate". This pulls up all matching items. You can then uncheck any items that you do not wish to show. Let me know if you have any questions.

Please try at
List B2

=INDEX($A$1:$A$48,AGGREGATE(15,6,ROW($A$2:$A$48)/ISNUMBER(SEARCH(CELL("contents")&"",$A$2:$A$48)),ROWS(B$2:B2)))

Data Validation List at Sheet1 A7

=OFFSET(List!$B$2,,,COUNTIF(List!$B$2:$B$48,">'"))
and uncheck Show error at Error Alert

Key some word in A7 and click the drop-down icon