noun
combo box
A graphical user interface widget combining a text field and a drop-down list. Technical computing term.
フォームにコンボボックスを追加してください。
Please add a combo box to the form.
Variant spelling with a middle dot; less common in running text.
A drop-down list only allows selection from a list, while a combo box also allows direct text input.
A text box is a simple text input field without a drop-down list.
Borrowed from English 'combo box', a compound of 'combo' (combination) and 'box'.