상단 메뉴, 풀사이즈 메뉴, 전체 메뉴, 가로 네비게이션, 중복실행 방지

* {margin: 0; padding: 0; }
li {list-style: none; }
body {font-family: 'Nanum Gothic', sans-serif; width: 1200px; margin: 0 auto; }
            
.logo {margin: 50px 0; font-size: 30px; text-align: center; font-family: 'Nanum Brush Script', cursive; }
            
.topMenu {width: 100%; margin-bottom: 20px; text-align: center; height: 40px; }
.topMenu:after {content: ""; display: block; clear: both; }
.menu01>li {float: left; width: 20%; line-height: 40px; }
.menu01 span {font-size: 20px; font-weight: bold; }
            
.dept01 {display: none; padding: 20px 0; border-bottom: 1px solid #ccc; }
            
#nop {float: none; }
            
.none:after {content: ""; display: block; clear: both; }

<div class="logo">
            <span class="logo">컨텐츠 내용이 밀리는 풀 드롭다운 메뉴</span>
        </div>
        <div class="topMenu">
            <ul class="menu01">
                <li><span>Menu01</span>
                    <ul class="dept01">
                        <li id="nop">sub01</li>
                        <li id="nop">sub02</li>
                        <li id="nop">sub03</li>
                        <li id="nop">sub04</li>
                        <li id="nop">sub05</li>
                    </ul>
                </li>
                <li><span>Menu02</span>
                    <ul class="dept01">
                        <li id="nop">sub01</li>
                        <li id="nop">sub02</li>
                        <li id="nop">sub03</li>
                        <li id="nop">sub04</li>
                        <li id="nop">sub05</li>
                    </ul>
                </li>
                <li><span>Menu03</span>
                    <ul class="dept01">
                        <li id="nop">sub01</li>
                        <li id="nop">sub02</li>
                        <li id="nop">sub03</li>
                        <li id="nop">sub04</li>
                        <li id="nop">sub05</li>
                    </ul>
                </li>
                <li><span>Menu04</span>
                    <ul class="dept01">
                        <li id="nop">sub01</li>
                        <li id="nop">sub02</li>
                        <li id="nop">sub03</li>
                        <li id="nop">sub04</li>
                        <li id="nop">sub05</li>
                    </ul>
                </li>
                <li><span>Menu05</span>
                    <ul class="dept01">
                        <li id="nop">sub01</li>
                        <li id="nop">sub02</li>
                        <li id="nop">sub03</li>
                        <li id="nop">sub04</li>
                        <li id="nop">sub05</li>
                    </ul>
                </li>
            </ul>
        </div>
        <div class="none">
        </div>

$(document).on('mouseover', '#header', function() {
        //$('.topMenuSub').slideDown(100);
	var $tMenu=$('.topMenuSub');
	if(!$tMenu.is(':animated')) $tMenu.slideDown(100)
    });

    $(document).on('mouseleave', '#header', function () {
        $('.topMenuSub').slideUp(100);
    });

 

 

애니메이션이 실행중이지 않을 경우만 적용시

if(!$('.topMenuSub').is(':animated')){

}

 

 

 

출처

miel0930.tistory.com/33